1. Technical Field
The present disclosure relates to a package, a light emitting device, and methods of manufacturing the package and the light emitting device.
2. Description of the Related Art
Various types of light emitting devices using a light emitting element and methods of manufacturing the same have been developed. For example, JP 2014-29995 A discloses a light emitting device having a linear protrusion at a lead frame, and a method of manufacturing the light emitting device. Also for example, JP 2004-274027 A and JP 2005-353914 A each disclose a light emitting device in which a portion of a lead frame forming a bottom surface of a recess is recessed to place a light emitting element therein, and a method of manufacturing the light emitting device.
Meanwhile, a method of manufacturing a light emitting diode (hereinafter referred to as an “LED”) includes molding a package, and an LED is manufactured through the molding step. In manufacturing an LED, transfer molding has been typically employed, in which a lead frame is set in a mold and liquid resin is injected. However, with such a method of manufacturing an LED, the resin flows into a gap between the lead frame and the mold, which may result in the generation of resin burrs. Such resin burrs may cause a bonding failure of LED elements and/or wires, so the burrs must be removed. Accordingly, in conventional manufacturing of an LED, the molding is always followed by removing burrs.
In such a method of manufacturing an LED, examples of ways to prevent generation of resin burrsinclude optimizing conditions in the molding, increasing the pressing force of the mold, reducing the number of LEDs molded with a single lead frame, increasing the viscosity of resin to reduce flowability or the like.
Further, JP2014-29995 A discloses that, in a lead frame provided with a plating layer on its surface, burrs can be reduced by allowing the plating layer to rise and protrude at the border of a portion where a metal portion is desired to be exposed (a LED mounting portion, a wire bonding portion).
The mold disclosed in JP 2014-29995 A is provided with a projection having a shape corresponding to a recess of a package. Accordingly, the mold has the following structure. When the lead frame is clamped, the projection of the mold abuts and is pressed against a linear protrusion formed by plating raised at the boundary of the LED mounting portion or the like. Thus, entry of resin which will become burrs is prevented.
However, in the method of manufacturing disclosed in JP 2014-29995 A, the width of the linear protrusion is small, so that formation of the protrusion on the lead frame is difficult.
In the light emitting device and the method of manufacturing the same disclosed in JP 2004-274027 A and JP 2005-353914 A, in order to facilitate control of the directivity of light and to improve the light-extracting efficiency, a portion of the lead frame forming the bottom surface of the recess is further recessed. Thus, neither of these disclosures discloses preventing the generation of burrs. Accordingly, the methods disclosed in JP 2004-274027 A and JP 2005-353914 A are insufficient to prevent generation of burrs.